Twyer for steam-boiler furnaces.



No. 650,362. Patented May 22, I900. S. J. SMITH.

TWYER FOR STEAM BOILER FURNACES.

Application filed Mar. 5, 1900.)

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by vbcwmewmagm No. 650,362. Patented May 22, I900. 8.1]. SMITH.

TWYER FOR STEAM BOILER FURNACES.

(Application filed Mar. 5, 1900.)

(No Model.)

2 Sheets-Sheet 2 Inventoram 77M&(

77/63 cfii-orney's.

THE cams PETERS co. PHOTO-LUNG. WASHINGTON a. c.

UNITED STATES 7 PATENT OFFice.

SAM J. SMITH, or LOWELL, MASSACHUSETTS.

TWYER FOR STEAM BOILE R FURNACES.

SPECIFICATION forming part of Letters Fatei'lt No. 650,362, dated May22, 1900.

Application filed March 5, 1900. Serial No. 71292. (No model.)

To an whom it may concern..-

Be it known that I, SAM J. SMITH, a citizen of the United States,residing at Lowell, in the county of Middlesex, State of Massachusetts,have invented a certain new and usef ul Improvement in Twyers forSteam-Boiler Furnaces, of which the following is a specification,reference being had therein to the accompanying drawings.

My invention relates to twyers, and espe cially to those which are usedin boiler-furnaces in connection with an underfeed Stoker, or one whichis adapted to introduce fresh fuel into the mass of burning fuel throughan opening directly beneath such mass and at the same time to introducefresh air into the same. My twyer is, however, useful in otherconnections, as will readily be understood.

The mouth of the twyer for un'derfeed stokers is composed of a series ofhollow blocks having air-openings disposed partly or wholly around theinner and outer faces thereof adjacent to the rim of the mouth. Such rimprojects upward into the mass of burning fuel, and therefore issubjected to a very intense heat. The twyer-blocks are attached at theirlower ends to the double shell of the body of the twyer and form acontinuation of the air-space in the shell through which a constantstream of fresh air passes to the fire, issuing through the air-openingsmentioned above. The twyer-blocks are of considerable size and weight,are difficult to cast, and are expensive to replace when made in asingle piece. The crown portion of the block cracks apart or burns outand renders frequent replacementnecessary. When a block is cracked orpartly burned out, fuel and slag enter the air-passages and choke them.Attempts have been made to furnish a removable crown for each blockwhich when cracked or burned out might be replaced by a new one withoutthe necessity of replacing the whole block. Serious difficulty has,however, arisen in respect to the attachment of such a crown to theremainder or base of the block, so as to permitits ready removal fromabove the twyer, while thoroughly protecting the bolts or otherattaching members from being melted by the intense heat and being thusrendered incapable of detachment. In fact, I am not aware of anyconstruction except my own in which the crown can be re moved by accessfrom above the twyer.

My invention is described in the following paragraphs, illustrated inthe accompanying drawings, and defined in the claims at the close ofthis specification.

In the drawings, Figure 1 is a front elevation of a twyer-block providedwith my improvement. Fig. 2 is a plan of the base. Fig. 3 is a sectionof the base and crown on the line 3 3 of Figs. 1 and 2. elevation of thesame parts. Fig. 5 is a front elevation of a modified form of base andcrown. Fig. 6 is a side elevation of the same, the interior arrangementbeing shown in dotted lines.

Only the twyer-block has been shown in the drawings, since its mode ofconnection to the double shell of the body of the twyer is wellunderstood.

Referring first to Figs. 1 to 4, 1 is the base and 2 the crown of thetwyer-block. 3 3 are air-openings on the inner or front face thereof,and 4t 4 are air-openings in the outer or rear face. 5 is an interiorpartition which prevents the air from issuing through the openings 3 3until it has come in contact with the under surface of the crown 2, andthereby the temperature of the crown is kept as low as possible. 6 isthe recess in the outer face of the side of the base in which rests theT- bolt attaching the base to the main body of the twyer.

In accordance with the first part of my invention I pass a bolt directlythrough the crown and into the air-space in the hollow interior of theblock, where it engages with holding means, into which it may be tightlyscrewed by rotating its exposed head from above the twyer. The said headis preferably countersunk in the upper face of the crown, and the recessabove it is filled with ashes, sand, asbestos, or other non-conductingand Fig. 4is a side ineombustible material, which may readilybe removedto obtain access to the bolt. By countersinking the head of the bolt Ibring it into contact with the metal of the crown, near the undersurface thereof, which surface is constantly cooled by the current ofair within the twyer-block. The remainder of the bolt and its holdingmeans are located directly in the said current, and thereby areperfectly protected from all liability of melting together. It may notbe found necessary in all cases and with all .degrees of heat tocountersink the head of the bolt in the crown;

but I prefer this construction. This portion of my invention isembodied, in Figs. 1 to 4 of the drawings, in a bolt 8, countersunk in arecess 7 in the crown and extending down into the air-space 30 in theblock, there passing through a slot 9 between cars 10 10, projectin gfromthe interior face of the base 1. There are preferably two bolts,850., one near each side, as shown. Below the slot 9 a nut 11 is turnedupon the bolt 8. In this construction the crown is applied to the'basewith the bolt inserted in it and the nut turned part way upon the bolt.The nut passes down between the partition 5 and the ears 10 10 till itcomes below the latter, and then the crown is pushed outward or backwarduntil the stem of the bolt enters the slot 9 and one face of the nutmakes contact with the interior surface of the base. Then the bolt isrotated from above, drawing the nut, which is prevented from rotation,snugly against the cars 10 10, and thereby clamping the crown and basetogether. This operation, of course, is performed while the base isattached to the main body of the twyer. A reverse operation detaches thecrown. The corresponding construction is shown in Figs. 5 and 6 asconsisting of a bolt 18, countersunk as before, and in this instance 7screwing directly into a threaded hole bored in the car 19. There are ormay be two of these bolts and cars.

In accordance with the second part of my invention I give such a shapeto the contiguous surfaces of the crown and base that all lateral strainis removed from the bolt by which they are attached together, while atthe same time the contraction and expansion to which the crown issubjected can occur freely without stress between the interlockingsurfaces aforesaid. Thus while Figs. 1 to 4 show simple shoulders 12 13,which may in ordinary cases prevent the inward and outward displacementof the crown, I prefer the improved construction illustrated in Figs. 5and 6 as suited to the most severe and prolonged strains, whilefulfilling the other requirements enumerated. The strain on the crown ismostly outward, for as the fuel being fed is ejected from the twyer intothe mass of burning fuel on the grate it grinds heavily over the inneredge of the mouth of the twyer and tends to displace outward the crownsthat or ribs 14 14 sliding in corresponding grooves in the base. Theshoulder 15 takes the outward strain completely. As to the lesser inward strain, the engaging ribs and grooves are so far below the level ofthe upper outer edge or the crowh where that strain is applied that thetendency is to tilt the crown instead of sliding it directly inward. Anytilting motion, however, is prevented by the bearing of the ribs in thegrooves. At the same time the expansion and contraction of the crown areallowed to take place freely, both laterally and vertically. Thereby thelife of the crown is very much extended.

That I claim is 1. In an air-feeding twyer-block, the (30111 bination ofa hollow base attached to the main body of the twyer, a removable crownengaging with the base, a bolt passing through a hole in the crown andinto the air-space in the base, and holding means located in theinterior of the base engaging with the bolt,- whereby the bolt may beloosened and tightened and the crown removed and. replaced by accessfrom above the twyer, substantially as described.

2. In an air-feeding twyer-block, the combination of a hollow baseattached to the main body of the twyer, a removable crown engagingwith'the base, a bolt passing through a hole in the crown and into theair-space in the base, and an ear projecting from the interior face ofthe base and engaging with the bolt, whereby the bolt maybe loosened andtightened and the crown removed and replaced by access from above thetwyer, substantially as described.

3. In an air-feeding twyer-block, the combination of a hollow baseattached to the main body of the twyer, a removable crown en'- gagingwith the base, the crown and base having corresponding deep shoulderswhich resist outward strain and corresponding ribs and grooves whichresist a tilting inward strain, whereby the crown is held fromdisplacement while free to expand and contract independently of thebase, substantially as described.

4. In an air-feeding twyer-block, the combination of a hollow baseattached to the main body of the twyer, a removable crown engaging withthe base, a bolt passing through a countersunk hole in the crown andinto the air-space inthe base, and holding means located in the interiorof the base engaging with the bolt, whereby the bolt may be 100sened andtightened and the crown removed any injured crown can be removed without10 and replaced by access from above the twyer, loosening the rest,substantially as described. substantially as described. In testimonywhereof I affix my signature 5. In an air-feeding tWyer-block, the cominpresence of two witnesses.

5 bination of a hollow base attached to the main 7 body of the twyer, aremovable crown en- SAM SMITH gaging with the base, and means of attach-Witnesses: ing together the crown and base of each block WM. A. MAGLEOD,A independently of every other block whereby ALICE H. MORRISON.

